docs: def pseudo_dir(source_path, cache_path=None, delete=Ellipsis, credentials=None, meta_data=None):
      '''
      pseudo_dir(source_path) yields a pseudo-directory object that represents files in the given
        source path.
  
      Pseudo-dir objects act as an interface for loading data from abstract sources. The given source
      path may be either a directory, a (possibly zipped) tarball, or a URL. In all cases but the
      local directory, the pseudo-dir object will quietly extract/download the requested files to a
      cache directory as their paths are requested. This is managed through two methods:
        * find(args...) joins the argument list as in os.path.join, then, if the resulting file is
          found in the source_path, this (relative) path-name is returned; otherwise None is returned.
        * local_path(args...) joins the argument list as in os.path.join, then, if the resulting file
          is found in the source_path, it is extracted/downloaded to the local cache directory if
          necessary, and this path (or the original path when no cache directory is used) is returned.
  
      The following optional arguments may be given:
        * cache_path (default: None) specifies the cache directory in which to put any extracted or
          downloaded contents. If None, then a temporary directory is created and used. If the source
          path is a local directory, then the cache path is not needed and is instead ignored. Note
          that if the cache path is not deleted, it can be reused across sessions--the pseudo-dir will
          always check for files in the cache path before extracting or downloading them.
        * delete (default: Ellipsis) may be set to True or False to declare that the cache directory
          should be deleted at system exit (assuming a normal Python system exit). If Ellipsis, then
          the cache_path is deleted only if it is created by the pseudo-dir object--given cache paths
          are never deleted.
        * credentials (default: None) may be set to a valid set of Amazon S3 credentials for use if
          the source path is an S3 path. The contents are passed through the to_credentials function.
        * meta_data (default: None) specifies an optional map of meta-data for the pseudo-dir.
      '''
      return PseudoDir(source_path, cache_path=cache_path, delete=delete, credentials=credentials,
                       meta_data=meta_data)